Description of problem:
User is able to set password shorter than 8 chars in the provisioning dialog.
Foreman api returns error 422 and the provisioning request fails.

Version-Release number of selected component (if applicable):
5.4.0.0.22

How reproducible:
Always

Steps to Reproduce:
1. Setup foreman
2. During provisioning, set pass shorter than 8 chars

Actual results:
CFME side:
----------
[----] E, [2015-04-23T16:25:35.060804 #2247:12bdea4] ERROR -- : Q-task_id([miq_provision_task_1])
 MIQ(MiqProvisionTaskConfiguredSystemForeman#provision_error) [[RestClient::UnprocessableEntity]:
 422 Unprocessable Entity] encountered during phase [update_configuration]


Foreman side:
-------------
Processing by Api::V2::HostsController#update as JSON
  Parameters: {"host"=>{"hostgroup_id"=>"1", "root_pass"=>"[FILTERED]"}, "apiv"=>"v2", "id"=>"3"}
Authorized user admin(Admin User)
Unprocessable entity Host::Managed (id: 3):
  Root password should be 8 characters or more

  Rendered api/v2/errors/unprocessable_entity.json.rabl within api/v2/layouts/error_layout (3.1ms
)
Completed 422 Unprocessable Entity in 7000ms (Views: 72.0ms | ActiveRecord: 89.2ms)


Expected results:
If the user chooses to pick a password, he/she must not be allowed to set one that is shorter than 8 characters.

Additional info:
-